Chromium alloys.



1,1753% Ho Drawing.

WIIIIBUB B. DRIVER,v DIE-EAST ORANGE, NEW JERSEY.

cnnomum annoys.

To all whom it may concern Be it known that I, WILBUR B. DRIVER, a

citizen of the United States, and a resident of the city ofEast Orange, State of- New Jersey, (whose post-oflice address is Middlesex' street,.Ha1 -rison, Newark, New J ersey,) have invented new and useful Chromium Alloys, which invention is fully set forth in the following specification;

' My invention relates to chromium alloys intended primarily for use as an electricalsome other metal such as manganese or nickel,,the chromium may be added in substantial quantitie (say, from about ten per cent. to almost twenty per cent.) and yet produce an alloy which is ductile and malleable, and which. affords a relatively highresistance to oxidation; moreover, the alloys of this newclass present a high electrical resistance and have a low temperaturecoefiicient, so that they are particularly suitable for electrical-resistance purposes.

Other things being equal, increase in the percentage of chromium increases the resistance .to oxidation, but decreases the workability of the composition. With as much as twenty per cent. of chromium, the mate-' rial appears rather difiicult to work; but with around ten per cent. of chromium, it works easily, and such 'ten per cent. chromium alloys are found-to be very suitable for electrical-resistance purposes. Even an per amount of chromium as low as two cent. produces a'markerl efiect.

Broadly my invention contemplates an allloy containing chrom1um,' niore specifically chromium and copper. {I prefer, however,

Specification of Letters Patent. Application filed June 24,1912. Serial No. 705,442.

the material is practically valueless, yet when the chromium is to be added to a mixture or alloy of copper and Patented Mar. 1a, 1916 an alloy comprising chromium and copper with some other metal or metals, and particul'arly such three-metal alloys in which there is a substantial percentage of the chro mium. The preferred amountof chromium is around ten per cent., although'the per- Y centage may vary as between, say, two per cent. and twenty per cent.

As one example, take about parts, by weight, of copper, about 45 parts of nickel,

'and about 10 parts of chromium, and fuse them together in any convenient manner. As another example, take about parts, by weight, of 'nickel, about 30 parts of copper, about 10 parts of manganese, and about 10 parts of chromium, and fuse them together in any convenient manner. The lowest temperature coeflicients havebeen obtained where the nickel and copper are used in about equal amounts, and as the nickel is increased the alloy becomes harder. But these nlckel-copper-chromium alloys, with or without manganese, give very good results, both, Where the nickel predominates and where the copper predominates. The

effect of the addition of chromium to alloys containing nickel and copper, increases as the percentage of the nickel increases. In other words, it seems as though the chromium has a greater effect, for electrical resistance, upon the nickel than upon the copper.

Having thus described my invention, 1 claim: 1. Anelectrical-resistance element consisting of an alloy containing copper and nickel and manganese, with from about two per cent. to about ten percent. (240%) of chromium.

2. An electrical-resistance element consisting of an alloy containing copper and nickel and manganese, with a substantial percentage of chromium.

In testimony whereof I have signed this specification in the presence of two subscribing witnesses. I v

v BUR B. DRIVER.

Witnesses: I

' GJA. L. Max-ism p 1 RALrn L. 

